Hibernate中根据QueryName查询
Hibernate中提供一种可以把HQL配置在Hibenate.hbm.xml中. 这样的好处,可以统一进行管理. 以及可以在其他Service中都能用到.
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比如我们在User.hbm.xml中配置如下HQL语句:
<?xml version="1.0" encoding="utf-8"?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"><!-- Mapping file autogenerated by MyEclipse Persistence Tools--><hibernate-mapping> <class name="pack.java.model.UserInfo" schema="MBADMIN" table="USER_INFO"> <id name="uiid" type="java.lang.Long"> <column name="UIID" precision="10" scale="0"/> <generator lazy="false" name="username" type="java.lang.String"> <column length="20" name="USERNAME" not-null="true"/> </property> <property generated="never" lazy="false" name="password" type="java.lang.String"> <column length="15" name="PASSWORD"/> </property> <property generated="never" lazy="false" name="groups" type="java.lang.String"> <column length="20" name="GROUPS"/> </property> <property generated="never" lazy="false" name="email" type="java.lang.String"> <column length="48" name="EMAIL"/> </property> <property generated="never" lazy="false" name="status" type="java.lang.String"> <column length="1" name="STATUS"/> </property> <property generated="never" lazy="false" name="lastlogintime" type="java.lang.String"> <column length="23" name="LASTLOGINTIME"/> </property> <property generated="never" lazy="false" name="failcount" type="java.math.BigDecimal"> <column name="FAILCOUNT" precision="22" scale="0"/> </property> <property generated="never" lazy="false" name="locktime" type="java.lang.String"> <column length="23" name="LOCKTIME"/> </property> </class> <query name="query_user_by_username">from UserInfo U where U.username = ?</query></hibernate-mapping>
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?? 然后,在Service中通过定义一个变量引用query中的name即可.
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private static final String QUERY_USER_BYNAME = "query_user_by_username";public List<UserInfo> queryUserByName(String name) {// TODO Auto-generated method stubList<UserInfo> list = new ArrayList<UserInfo>();try {list = userDao.queryUserByName(QUERY_USER_BYNAME, name);} catch (DatabaseException e) {// TODO Auto-generated catch blocke.printStackTrace();System.out.println("查询出现异常!");}return list;}?
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?? UserDao中的方法如下:
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public List<UserInfo> queryUserByName(String queryName,Objcect...objects)throws DatabaseException {Query query = getSession().getNamedQuery(queryName);??if(objects!=null && objects.length > 0 ){???for(int i = 0 ;i<objects.length;i++){????query.setParameter(i, objects[i]);???}??}??return query.list();}?